How severe is CVE-2016-6556?

CVE-2016-6556 has a CVSS 3.x base score of 7.1, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity low, and availability none.

Is CVE-2016-6556 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (52nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2016-6556?

CVE-2016-6556 affects Opennms. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2016-6556?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2016-6556 published?

CVE-2016-6556 was published on 2021-09-24 and last updated on 2026-06-17.

CVE-2016-6556

CVE-2016-6556 is a high-severity vulnerability in Opennms with a CVSS 3.x base score of 7.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

Severity: High (CVSS 3.x base score 7.1)
CVSS v2: 4.3
EPSS exploit prediction: 1% (52nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Opennms
Published: 2021-09-24
Last modified: 2026-06-17

Description

OpenNMS version 18.0.1 and prior are vulnerable to a stored XSS issue due to insufficient filtering of SNMP agent supplied data. By creating a malicious SNMP 'sysName' or 'sysContact' response, an attacker can store an XSS payload which will trigger when a user of the web UI views the data. This issue was fixed in version 18.0.2, released on September 20, 2016.

Frequently asked questions

What is CVE-2016-6556?: OpenNMS version 18.0.1 and prior are vulnerable to a stored XSS issue due to insufficient filtering of SNMP agent supplied data. By creating a malicious SNMP 'sysName' or 'sysContact' response, an attacker can store an XSS payload which will trigger when a user of the web UI views the data. This issue was fixed in version 18.0.2, released on September 20, 2016.
How severe is CVE-2016-6556?: CVE-2016-6556 has a CVSS 3.x base score of 7.1, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity low, and availability none.
Is CVE-2016-6556 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (52nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2016-6556?: CVE-2016-6556 affects Opennms. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2016-6556?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2016-6556 published?: CVE-2016-6556 was published on 2021-09-24 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:opennms:opennms:*:*:*:*:*:*:*:*

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